Perfect Vanilla Cupcakes

For the cupcakes:
Preheat oven to 180ºC (350ºF or Gas 4). Line a 12-cup muffin tin with muffin cases, and set aside.

Whisk together flour, baking powder, baking soda, and salt. Set aside.

Whisk eggs. Add sugar and whisk until combined. Add vanilla extract, butter, and sour cream, and whisk until combined. Fold in the dry ingredients.

Divide batter evenly between the muffin cases, filling only 2/3 full. Bake 14–16 minutes, or until a toothpick inserted into the center comes out clean. Allow to cool for 5 minutes in the pan, before transferring them to a wire rack to cool completely before frosting.

For the frosting:
Using a handheld or stand mixer, beat together butter and icing sugar until light and fluffy. Beat in milk and vanilla extract until smooth and spreadable. Transfer frosting to a piping bag, and frost the cooled cupcakes.